Conventionally, a fixed network, a mobile network, and a local area network (LAN) are used as communication paths by which communication terminals communicate with each other. However, due to recent increasing communication demand, increased capacity and range of each communication path is required, the provision of optical fibers capable of data multiplexing and relay apparatuses for the mobile network and the wireless LAN has been progressing.
Meanwhile, a technique of utilizing digital broadcast waves has been researched as a new communication path for bidirectional communication. Conventionally, broadcast waves have been used to convey data, such as content (programs), to the general public. However, a technique of digitalizing broadcast waves has enabled broadcast waves carrying data in packets.
By such digital broadcast waves, bidirectional communication has been enabled between the transmitting side and the receiving side. In this technique, data can be exchanged via the Internet, a receiver that has received a digital broadcast can acquire information concerning a bidirectional web server related to the concerned broadcast content and communicate with the web server via the Internet, etc. (see, for example, Patent Document 1 below).    Patent Document 1: Japanese Patent Application Laid-open Publication No. 2003-78830